When it opened its doors during the final chapter of both the Carter Administration and the disco movement, it was touted as the Chicago area’s first IMAX screen — and, in commercials you couldn’t miss during the spring and summer of 1979, as “the world’s largest motion picture experience.”

But when it was torn down this spring, the Pictorium at Six Flags Great America merely qualified for a mention on Twitter.

“And just like that, we say farewell to Pictorium. Thanks for 40 years of memories! Time for new thrills!” reads a May 4 tweet from @SFGreat_America, showing a time lapse of a demolition crane chipping away at the Hometown Square building that housed the 96-by-65-foot screen.

It was an abrupt and unceremonious ending for one of the park’s ancestral attractions, especially considering its history as a giant-screen pioneer. Adding insult to injury, the video embedded in the tweet generated about 4,200 views in the past month.

But anyone who ever entered the dark sanctum of the Pictorium had to feel at least a small twinge of nostalgic sorrow when learning that the end had come. Even if you weren’t a fan of watching movies on a 10-story screen, you had to like the Pictorium for the other role it filled: Shelter.

On a hot July afternoon or a cold night during Fright Fest or on one of the many operating dates when Great America stubbornly forges onward despite unreasonable conditions, the Pictorium was a rock-solid option to escape the elements for about an hour or so.

The immense auditorium — one online IMAX database claims it held 980 seats — was nothing if not an oasis from even a good day at the park when you reached that point where you’d been walking on asphalt in the summer sun for six hours and just needed to get off your feet and into a climate-controlled environment.

Raise your hand if you caught some of the best sleep in your life inside the Pictorium. No need to feel ashamed. Some of the movies featured there were memorable, including the very first, “To Fly!” Others were seemingly designed for a power nap. The Great America-history documentary series “Screams and Dreams” comes to mind.

Back in October 2005, Fright Fest featured something called “Haunted Castle,” a 3-D offering that offered five minutes of expository dialogue for every one cool visual. The most interesting development came when someone in the audience checked their phone and shouted out that the White Sox had won Game 3 of the American League Championship Series.

But the old movie fortress was invaluable on those occasions when Mother Nature went from merely annoying to truly dangerous. One summer when my kids were young and smartphones were new, we noticed on a weather app that a nasty thunderstorm was barreling in from the west. We got out of Hurricane Harbor before an evacuation was announced over the loudspeakers and headed straight for the Pictorium, figuring it would be an ideal place to ride out the storm while watching a movie.

It turned out we weren’t the only ones who had that brilliant idea. In fact, the theater operators cancelled whatever screening was supposed to take place and opened the doors for anyone who wanted to huddle inside while the hailstorm roared outside.

Dan Moran / News-Sun

Officials at Six Flags Great America are playing coy about what will replace the Pictorium in 2019 after the old IMAX theater was torn down in early May. The site is now surrounded by fencing and signs with a vague hint.

Officials at Six Flags Great America are playing coy about what will replace the Pictorium in 2019 after the old IMAX theater was torn down in early May. The site is now surrounded by fencing and signs with a vague hint. (Dan Moran / News-Sun)

And now it is gone, along with untold thousands of memories of sitting down to blessed relief, if not unforgettable entertainment. What was once the Pictorium is now a field of waterlogged mud and gravel with a trench where the auditorium sloped downward.

What will take its place? Great America officials are being strategically evasive as usual, simply postings signs around the work zone about “Big Thrills” coming soon. A park spokeswoman held to that line when pressed for more information this week, saying via email only that, “We are making space for future thrills!”

While it remains to be seen how aggressive Great America will be to keep up in the unrelenting competition between big-ticket theme parks, it can be said for now that — as was the case last year — a virtual reality element will be added later this month to the Giant Drop in Southwest Territory.

From June 21 and through July 22, riders wearing VR headsets will experience “DC Super Heroes Drop of Doom,” which will allow said riders to “do battle alongside their favorite super heroes before plunging down over 200 feet on our Giant Drop,” according to a park statement released early Tuesday.

It could be argued that the thrill of dropping 200 feet as if falling off a cliff does not need much more in the way of added excitement, but this is 2018. Whatever keeps theme park rides fresh and popular might just keep them from going the way of the Pictorium — may it rest in pieces.